Royal Mail's target delivery times for air mail are as follows:
Western Europe: 3 days
Eastern Europe: 4 days
Rest of the World: 5 days
If you pay an extra �4 for the AirSure service, the above targets are all reduced by 1 day.
My personal experience of sending and receiving air mail (without the AirSure service) has been that items to/from nearby European countries take between 1 and 3 days. (I've received an item in Suffolk only 18 hours after it was posted in Holland ). Items to/from the USA nearly always take exactly 5 days.
Chris